In conducting certain medical tests and surgical procedures, it is usual to insufflate a gas, usually CO2, in a patient's cavity.
Gas heating for medical insufflators is very important. For certain invasive surgery, such as laparoscopy, hysteroscopy, or others, heating of the gas is important to prevent fog on camera lenses and dropping of the patient's temperature during the procedure.
For other procedures such as virtual colonoscopy, it is also convenient to supply hot gas because it relaxes the patient's muscles, enhances distension and reduces the risk of spasms
Currently there are insufflator systems that incorporate heating means for the gas to be supplied to the patient.
The trouble with high flow insufflators (applicable in procedures such as laparoscopy or hysteroscopy) is the significant variation in flow and room temperature. The gas flow supplied must be continuously regulated to maintain pressure as constant as possible in the insufflated cavity. This flow may vary from 0 to 50 liters/minute during the test or procedure to be performed.
Currently insufflators, having a gas inlet, a valve that regulates the flow of gas to be supplied, and an outlet for supplying the gas, to which a disposable duct that conveys the insufflator supplied gas into a patient's cavity is coupled, are well known. These insufflators are also currently used in combination with a gas heater.
In some cases, the gas heater is arranged inside the insufflator, heating the gas before it leaves the insufflator.
The problem with this technology is that an exact temperature cannot be reached inside the patient. Due to the fact that the duct arranged between the machine and the patient is of a certain length and that the temperature of the room is usually from 12° C. to 25° C., there is a great loss of calories during the transit of gas through the duct, between the patient and the insufflator. This loss of calories depends on the room temperature and the flow. If the flow is stopped or is very low, then the gas available in the duct is cooled and when the flow circulates again, the cool gas contained in the duct is automatically pushed into the patient. It is also very difficult to calculate the heat setting when the flow frequently changes from 0 to 50 liters/minute.
Heating systems, in which the heater is arranged outside the insufflator, are also well known, specifically at an area near the end of the duct that is intended to be introduced into a patient's cavity.
This solution has the advantage of preventing the loss of calories in the gas available in the duct, between the machine and the patient, but this heating system is very difficult to regulate in order to obtain a constant temperature at the output of the duct. This system requires regulation of the heater on the basis of the variable gas flow supplied to the patient and use of a heater with low reaction time that may be stopped or heated when the gas flow changes. Therefore it is necessary to accurately adapt the heating to the gas flow introduced into the patient. These constraints cause that this heating system typically has a very low precision.
The technical problem, which arises in this invention, is the development of a system for heated gas insufflation in patients, which allows for continuous gas supply available at the duct outlet, just before the patient's cavity, at a very precise and constant temperature, irrespective of changes in the flow of gas intended to be introduced into the patient's cavity.